The response of gamma delta T cells to Plasmodium falciparum is dependent on activated CD4+ T cells and the recognition of MHC class I molecules

Immunology. 1996 Nov;89(3):405-12. doi: 10.1046/j.1365-2567.1996.d01-762.x.

Abstract

Peripheral blood gamma delta T cells from non-exposed individuals respond to antigens of the malaria parasite, Plasmodium falciparum, in vitro. This response, largely caused by T cells bearing the V gamma 9+ chain of the T-cell receptor, is stimulated by components of the parasite expressed on the schizont stage and released at schizont rupture. The response of V gamma 9+ T cells to parasite components is inhibited by antibodies to major histocompatibility complex (MHC) class I and class II. However, the inhibition by anti-MHC class II antibodies can be overcome by the addition of interleukin-2 (IL-2) to the cultures, suggesting that gamma delta T cells themselves do not recognize MHC class II molecules but require an MHC class II-dependent response taking place in the culture. In contrast, the inhibition by anti-class I antibodies cannot be reversed by addition of IL-2. Since an accompanying CD4+ T-cell response occurred in peripheral blood mononuclear cells cultured with P falciparum antigens, it was considered that these cells provide the cytokines necessary for the subsequent activation and expansion of V gamma 9+ T cells recognizing components of the parasite and MHC class I molecules. This was confirmed by reconstituting the response of enriched gamma delta T cells to P falciparum schizont extract by addition of purified CD4+ T cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, Protozoan / immunology*
  • CD4-Positive T-Lymphocytes / immunology*
  • Cell Culture Techniques
  • Dose-Response Relationship, Immunologic
  • HLA-D Antigens / immunology
  • Histocompatibility Antigens Class I / immunology*
  • Humans
  • Interleukin-2 / immunology
  • Lymphocyte Activation / immunology
  • Plasmodium falciparum / immunology*
  • Receptors, Antigen, T-Cell, gamma-delta / analysis*

Substances

  • Antigens, Protozoan
  • HLA-D Antigens
  • Histocompatibility Antigens Class I
  • Interleukin-2
  • Receptors, Antigen, T-Cell, gamma-delta